The present invention relates to surgical instruments comprising retractors and a method of controlling such instruments. The invention is particularly applicable to endoscopic surgical instruments.
EP 0 623 004 discloses a surgical instrument comprising a retractor.
US2006/0178562 discloses methods and apparatus for obtaining endoluminal access comprising a steerable endoluminal guide having a variable pivot for altering steering dynamics.
US2009/0079821 discloses a steerable structure (21, 27) of the catheter or endoscope type, the structure comprising an elastically or deformable longitudinal body (22, 28) including at least one actuator (16, 38) of material of the shape memory type incorporated longitudinally with the body (22, 28) together with Joule-effect heater means enabling the actuator (16, 38) to be contracted longitudinally in order to cause the longitudinal body (22, 28) to bend.
U.S. Pat. No. 5,308,342 discloses a catheter composed of an outer coaxial tube or relatively high flexibility and three tandemly disclosed inner coaxial tube segments that vary in stiffness with the stiffest being located a the proximal end of the catheter and the least stiff ending proximal of the proximal end of the catheter.
GB 2 456 165 discloses a shaft 1 for an endoscopic instrument having two series of slots 5 and 6 forming a preferentially flexible portion 2. The series are offset and the length of the slots varies along at least one of the series to vary the flexibility of the shaft.
WO 01/23022 discloses an endoscope having an elongated flexible sheath (12), A first sleeve (20) has a passage (24) therethrough which snugly received the sheath (12), the first sheath (12) being slidable from its proximal end to its distal end.